WTF::notFound looks too much like a local variable.

Source/core/html/track/TextTrackRegionList.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 51 matching lines @@
 }
 
 void TextTrackRegionList::add(PassRefPtr<TextTrackRegion> region)
 {
     m_list.append(region);
 }
 
 bool TextTrackRegionList::remove(TextTrackRegion* region)
 {
     size_t index = m_list.find(region);
-    if (index == notFound)
+    if (index == kNotFound)
         return false;
 
     m_list.remove(index);
     return true;
 }
 
 void TextTrackRegionList::clear()
 {
     m_list.clear();
 }
 
 } // namespace WebCore
 
 #endif